Hepatocellular adenoma and focal nodular hyperplasia are two benign hepatic tumors which are mainly detected in healthy young women. Hepatocellular adenoma is an indication for surgery due to the risk of haemorrhage and malignant transformation. By contrast, focal nodular hyperplasia should be managed conservatively. However, precise diagnosis of these benign liver tumors remains difficult and sometimes impossible, despite new imaging techniques. Because of the risk of diagnostic error, resection or large biopsies of presumed liver tumors should be performed in young women (and a fortiori in men and older patients in whom focal nodular hyperplasia is less prevalent) when the diagnosis of focal nodular hyperplasia is not firmly established. The risk of liver surgery in young patients with normal liver parenchyma is, in the opinion of the authors, lower than the risk of a mistaken diagnosis.